1. Field of the Invention
This application claims the benefit of priority to Japanese Patent Application No. 2004-165534, filed on Jun. 3, 2004, herein incorporated by reference.
The present invention relates to a thermal transfer printer, more specifically, to a thermal transfer printer capable of reducing cost by reducing the number of the components of the ribbon cassette.
2. Description of the Related Art
A conventional thermal transfer printer 31 will be described with reference to a drawing.
As shown in FIG. 3, the thermal transfer printer 31 includes a printer main body 31a, and a cassette mounting section 31b capable of mounting a ribbon cassette 39 to be described later in the printer main body 31a. 
A rotatable platen roller 32 is arranged in the printer main body 31a, and a thermal head 33 is arranged on the platen roller 32.
A recording paper 34 is fed between the thermal head 33 and the platen roller 32 so as to be carried in the direction of an arrow A.
The thermal head 33 is supported by a head mounting table 35 which is mounted on a head lever 36. The head lever 36 is turned about a supporting shaft 37 as a fulcrum, so that the thermal head 33 can be brought into contact with and separated from the platen roller 32 (head up/down).
When a ribbon cassette 39 to be described later is mounted on the cassette mounting section 31b in a state in which the thermal head 33 is separated from the platen roller 32 (head up), an ink ribbon 38 is positioned between the platen roller 32 and the thermal head 33.
The ink ribbon 38 is formed to have a slightly wider width than the recording paper 34 and both ends of the ink ribbon 38 are wound around a supply reel 39a and a take-up reel 39b, respectively. The supply reel 39a and the take-up reel 39b are rotatably supported in ribbon housing sections 39c facing each other so as to be housed in the ribbon cassette 39.
When the ribbon cassette 39 is mounted on the cassette mounting section 31b, the take-up reel 39b is engaged with a take-up bobbin (not shown) of the printer main body section 31a so as to be rotated by the rotation of the take-up bobbin.
When the take-up reel 39b is rotated in the counterclockwise direction by rotating the take-up bobbin in the counterclockwise direction, the ink ribbon 38 wound around the supply reel 39a can be wound around the take-up reel 39b. 
Further, the ribbon cassette 39 is provided with a relief groove 39d for relieving a pressing roller 41 to be described later, and a take-up port 39e is provided in the lower portion of the relief groove 39d. In addition, a guide roller 39f made of metallic rod is rotatably supported on a side plate adjacent to the take-up port 39e. 
The ink ribbon 38 to be wound around the take-up reel 39b is detached at a predetermined detachment angle from a ribbon detaching member 42 provided downstream in the ribbon-feeding direction of the thermal head 33. Then, the ink ribbon 38 is bent substantially orthogonally by the guide roller 39f so as to be wound around the take-up reel 39b. 
In addition, a paper feeding roller 40 and a pressing roller 41 which is pressed against the paper feeding roller 40 are arranged on the left side of the platen roller 32 in FIG. 3. The recording paper 34 is interposed between the paper feeding roller 40 and the pressing roller 41 so that the recording paper 34 can be carried in the direction of the arrow A by the rotation of the paper feeding roller 40 in the counterclockwise direction.
When the ribbon cassette 39 is mounted on the cassette mounting section 31b, the pressing roller 41 is positioned in the relief groove 39d. 
The above-mentioned conventional thermal transfer printer is described in Japanese Unexamined Patent Application Publication Nos. 2002-144616 and 2002-120446.
However, since the above-mentioned conventional thermal transfer printer 31 uses the high-cost guide roller 31 made of metal in the ribbon cassette 39, cost is increased.
In addition, when the ink ribbon 38 of ink is used up, the ribbon cassette 39 is discarded. In this case, since the guide roller 39f made of metal is also simultaneously discarded, resources are wasted.